THE ABDOMINAL WALLS. 93 



Posterior portion of the sheath, 435. (431) 

 Fold of Douglas. Transversalis fascia. 



Divide the transversalis at its origin from Poupart's ligament and carefully raise and turn forward a 

 small portion of the lower part of the muscle, exposing the transversalis fascia. 



Transversalis fascia, 436. (431-2) 



Deep crural arch. Internal abdominal ring. Infundibuliform fascia. 



At the lower part of the abdomen, the parts should now be carefully replaced and their relations con- 

 sidered with reference to the occurrence of inguinal hernia. 



Parts Concerned in Inguinal Hernia, 1159 to 1165. (1135 to 1141) 

 External Ring : 



Formation. Boundaries. Shape. 



Intercolumnar fascia. External spermatic fascia. 



Effect of the Position of the Thigh on the Ring. 

 Inguinal Canal : 



Length. Direction. Boundaries. 

 Internal Ring: 



Site. Shape. Dimensions. Boundaries. 

 Forms of inguinal hernia : 



(A) The Common Form : External, or Oblique. 



(B) Rarer Form : Internal, or Direct. 



A. Oblique, External Inguinal Hernia, coverings of : 



(1) At the internal ring, or inlet. 



(2) In the canal. 



(3) At the external ring, or outlet. 



B. Direct or Internal Inguinal Hernia, coverings of: 



Make a median incision through the abdominal wall, from the lower end of the sternum to the umbili- 

 cus. Make a transverse incision just above the umbilicus. Draw the flaps thus formed out and up, 

 and stitch them in place. Raise the lower portion of the abdominal wall and examine the inner sur- 

 face in the inguinal region. 



Posterior aspect of inguinal hernia : 

 Cords and fossae. 



Three cords : Urachus. 



Obliterated hypogastric arteries. 

 Three fossae : Internal, middle fossa, external fossa. 

 Causes of Hernia : 



(1) Hereditary. 



(2) Weak Spots. 



(3) (4) (5) (6) (7) (8) (9) O) () 



Parts Concerned in Umbilical Hernia, 1169-70. (1145-6) 

 Congenital umbilical hernia. 

 Infantile umbilical hernia. 



Prevented by: Changes in the Ring Itself. 



Changes in the Vessels Themselves. 

 Umbilical hernia of adult life. 

 Coverings of an umbilical hernia. 



Continue the division of the abdominal wall to the pubis, carrying the incision one-half an inch to the 

 left of the median line. Xote again the position of the obliterated hypogastric arteries and the urachus. 

 The scrotum and spermatic cord will next be considered. 



Make an incision from the external ring to the tip of the scrotum, in line with the spermatic cord, 

 reflect the skin and expose the dartos. Demonstrate the septum scroti. 



The Scrotum, 1060-1. (1038-9) 

 Scrotal integument, raphe. 



Superficial lymphatics of the scrotum, 700. (685) 

 Dartos. 



Septum scroti. 



